in this california school, the day started with a mock lockdown drill. >> stay in lockdown mold until you hear an all clear announcement. >> reporter: the other challenge for teachers and principals today, what to say to their students. >> we tell them that somebody was a very sick person, made some very poor choices and that is rare. that normally, usually, schools are safe places. >> reporter: and in georgia, parents left nothing to chance, walking their kids all the way into school, hand in hand. and while some parents did keep their children out of school today, experts recommend getting your children back to a normal ree tune, as soon as possible. that is made, though, particularly difficult here in connecticut, where the governor has ordered a moment of silence on friday. diane? >> all right, amy, thank you. >>> and we move next to the investigation there. police canvassing gun shops and firing ranges within 15 miles of newtown, connecticut, searching for more clues about the gunman and his mother. and tonight, some of those who knew them are coming forward to us with details ab